(a) Field of the Invention
An exemplary embodiment of the present invention relates to an active hood system of a vehicle. More particularly, the present invention relates to an impact detecting sensor assembly for an active hood system that detects an impact with a pedestrian so as to control an operation that raises a hood when a vehicle collides with the pedestrian.
(b) Description of the Related Art
Generally, an engine compartment is provided at a front portion of a vehicle, and the engine compartment is opened or closed by a hood. The hood of the vehicle opens or closes the engine compartment and also covers the engine compartment to muffle engine noise. Both sides of a rear end portion of the hood are engaged with a vehicle body of an upper portion of an engine compartment through a hood hinge assembly, and the hood rotates based on the hood hinge assembly to open or close the engine compartment.
Recently, investigations for a vehicle structure and a safety apparatus are being actively conducted in advanced countries to consider safety of a driver as well as safety of a pedestrian. When a vehicle collides with a pedestrian, if a predetermined distance between a hood and components (engine, etc.) is secured, the hood can absorb impact when a head of a pedestrian collides with the hood. However, in a case that the distance between the hood and the components is not sufficient, the head of a pedestrian collides with the hood and other components to be seriously injured.
By considering this point, in recent years, when a pedestrian collides with a vehicle, an actuator operation forcibly raises a rear end portion of a hood to absorb an impact of a pedestrian and simultaneously reduce an injury level by acting as an active hood system.
In this active hood system, it has to accurately determine whether a vehicle collides with a pedestrian, and for this purpose, it has to detect which part of a bumper collides with a pedestrian and determine whether an active hood system is operated.
The active hood system for this purpose includes an impact detecting sensor that detects a position where a pedestrian collides with a front bumper and an impact level thereof. An impact detecting sensor of an active hood system is disposed between an energy absorber of a front bumper and a bumper beam to detect an impact force when a vehicle collides with a pedestrian.
Accordingly, when a front bumper collides with a pedestrian, if an impact detecting sensor detects the collision, an active hood system is operated by an actuator of an electronic control unit and raises a rear end portion of a hood depending on a detection signal of the impact detecting sensor to secure a shock absorbing space between the hood and the engine compartment.
An impact detecting sensor of an active hood system according to a conventional art is disclosed in Korea Patent Laid-Open Publication No. 2014-0023048. An impact detecting sensor of an active hood system of this conventional art includes an optical fiber sensor and a membrane switch between a front element and a rear element that are disposed at a front surface of a bumper beam.
However, the impact detecting sensor of an active hood system according to a conventional art applies an optical fiber sensor and a membrane switch, and their cost is high and a complicated production process is necessary.
Also, an impact detecting sensor of an active hood system according to a conventional art is fabricated to correspond to various shapes of bumper beams, which is disadvantageous in terms of design freedom, continuous production is impossible, and it is disadvantageous in terms of production cost.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.